Method for inserting synthetic fibers into a surface, as well as a device for carrying out the same

ABSTRACT

Method and device for inserting synthetic fibres into a surface, wherein a fibre is unwound from at least one roll. The fibre is transported through a tube to a position under an insertion element by an air flow and is subsequently cut off to a desired length. The fibre is then pressed into the surface by an inserting element. The fibre is cut off by a rotatable element which is rotatable about an axis, which rotatable element is provided with a passage which is co-axial with the tube in a first position of the rotatable element and which includes an angle with the tube in a second position of the rotatable element, in which position the fibre is cut off.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The invention relates to a method for inserting synthetic fibres into asurface, wherein a fibre is unwound from at least one roll, said fibreis transported through a tube to a position under an insertion elementby means of an air flow, after which the fibre is cut off to a desiredlength, whereupon the fibre is pressed into the surface by means of aninsertion element.

The invention furthermore relates to a device which is suitable forcarrying out such a method.

(2) Description of Related Art

In a device of this kind, which is known from U.S. Pat. No. 3,937,158, afibre which has been unwound from a roll is passed through a tube andpositioned a desired length beyond the insertion element by means ofspecific guiding and clamping devices.

Each tube of the known device comprises at least two tube members whichare movable relative to each other, wherein a knife can be moved betweenthe tube members when said tube members are being moved apart. The fibrethat extends through the tube is cut off by means of said knife. Onedrawback of such a method for cutting off fibres is that there is a riskof a fibre end getting wedged between the two tube members when saidtube members are moved back towards each other, as a result of whichfurther transport of the fibre is no longer possible. Furthermore thereis a possibility of dirt finding its way into the tube members when thetube members are spaced apart. Furthermore there is a risk of operatingstaff injuring themselves on the knife in this position of the tubemembers.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is to provide a method and a device whereinthe fibre can be cut off in a simple manner.

This objective is accomplished with the method according to theinvention in that the fibre is cut off by means of an element which isrotatable about an axis, which element is provided with a passage whichis co-axial with the tube in a first position of the rotatable elementand which includes an angle with the tube in a second position of saidrotatable element, in which position the fibre is cut off.

Rotation of the element causes the fibre to be cut off by the edge ofthe passage and the edge of the tube. When the element is returned tothe original position, an uninterrupted passage through the tube isobtained again. Thus a correct guidance of the fibre is ensured. As aresult of the presence of the tube and the rotatable element, asubstantially completely closed system is obtained, whereinsubstantially no dirt can penetrate and wherein the risk being injuredupon cutting of the fibre is excluded.

Preferably, the diameter of the tube member on one side of the rotatableelement is larger than that of the tube member on the other side of therotatable element. This makes it possible to ensure that the fibre isonly cut off near the transition between the element and the tube memberhaving the smaller diameter, whilst the fibre is not cut off near thetransition between the tube member having the larger diameter and theelement.

One embodiment of the method according to the invention is characterizedin that the device furthermore comprises a guide tube which is co-axialwith the tube, which guide tube is positioned on a side of the tuberemote from the insertion element and which is axially movable withrespect to the tube from a first position, in which a substantiallyuninterrupted passage between the tubes is provided, to a secondposition, in which a passage for the insertion element is provided.

The presence of the movable guide tube likewise ensures a correctguidance of the fibre.

Such guidance is in particular important when the fibre is transportedby means of an air flow, since the absence of an effective guidancemight lead to uncontrolled fibre movement under the influence of the airflow.

The air flow ensures that the fibre remains elongate and clear of thewalls of, for example, a tube. This enables easy transport of the fibre,without there being a need to take hold of the end of the fibre.

As soon as the fibre extends sufficiently far beyond the insertionelement, the fibre is cut off and pressed into the surface.

Another embodiment of a method according to the invention ischaracterized in that the fibre is passed through a venturi device,wherein the air flow that carries the fibre is generated in the venturidevice.

The venturi device makes it possible to generate a desired air flow inan efficient manner.

Another object of the invention is to provide a device by means of whichfibres can be processed in a more efficient manner.

This objective is accomplished with the device according to theinvention in that the device comprises a fibre clamping and cuttingdevice, which comprises an element which is rotatable about a centralaxis, which element is provided with a passage which is co-axial withthe tube in a first position of the rotatable element and which includesan angle with the tube in a second position of said element.

The fibre can be cut off in a relatively simple manner by means of therotatable element.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail with reference to thedrawings, wherein:

FIGS. 1A and 1B are a top plan view and a side elevation, respectively,of one embodiment of a device according to the invention;

FIG. 2 is a larger-scale view of the portion II of the side elevation ofFIG. 1B, which shows a fibre cutting device comprising a knife;

FIG. 3 is a larger-scale view of the portion III of the side elevationof FIG. 2;

FIG. 4 is a larger-scale view of the portion IV of the side elevation ofFIG. 2;

FIG. 5 is a larger-scale view of the portion of the side elevation ofFIG. 1B of one embodiment of a device comprising a cutting deviceaccording to the invention; and

FIGS. 6 and 7 are side elevations of a second embodiment of a deviceaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Parts corresponding to each other are indicated by the same numerals inthe figures.

FIGS. 1A and 1B are a top plan view and a side elevation, respectively,of a device 1 according to the invention, which comprises a frame 3supported by caterpillar tracks 2. Frame 2 rotatably supports a numberof rolls 4, on which fibres are wound. Associated with each roll 4 is afibre insertion device 5, which will be explained in more detail withreference to FIG. 2. The fibre insertion devices 5 are arranged inside-by-side relationship in two parallel rows, so that two rows offibres can be simultaneously inserted into the surface with each go.

FIG. 2 is a larger-scale view of the portion II of the side elevation ofFIG. 1B, wherein a single fibre insertion device 5 is shown. Each fibreinsertion device 5 comprises a fibre feed-through tube 6 connected toroll 4, which tube opens, on a side remote from roll 4, into afeed-through plane 9 between two opposed wheels 7, 8. Wheels 7, 8 arerotatable in opposed directions as indicated by arrows P1, P2. A tube 10is disposed opposite wheels 7, 8, on a side remote from feed-throughtube 6. The central axis 11 of tube 10 lies in feed-through plane 9. Oneend of tube 10 remote from wheels 7, 8 opens into a venturi device 12,which will be explained in more detail with reference to FIG. 4. A tube13, whose central axis 14 coincides with the central axis 11 of tube 10,extends from the venturi device 12. A fibre cutting device 15, whichcomprises a knife 17 which is rotatable about a central axis 16, isprovided on a side of tube 13 remote from the venturi device 12.Disposed on a side of knife 17 remote from tube 13 is a fibre clampingdevice 18, which will be explained in more detail with reference to FIG.3. At a location beyond fibre clamping device 18, fibre insertion device5 includes a fibre feed-through channel 19, whose central axis 20coincides with axes 11 and 14. Fibre feed-through channel 19 terminatesin an end plate 21. Disposed between fibre clamping device 18 and endplate 21 is a fibre insertion device 22, which comprises a fibreinsertion pin 23, which extends transversely to central axes 11, 14, 20.Disposed under fibre insertion pin 23 are the fibre feed-through channel19, a guide channel 24 disposed thereunder and an opening 26 in apress-down plate 25. Fibre insertion pin 23 and press-down plate 25 canbe moved independently of each other in a direction indicated by arrowP3 and in a direction opposite thereto by means of bellows 27, which canbe actuated by means of compressed air. Before explaining the operationof the device 5 that is shown in FIG. 2, the fibre clamping device 18and the venturi device 12 that are shown in FIGS. 3 and 4 will first bedescribed in more detail.

FIG. 3 shows a clamping device 18, which includes a bellows 28 made ofan elastically deformable material, such as rubber, which is disposed ina chamber 29. A feed-through channel 30, whose central axis coincideswith axes 11, 14, 20, extends through chamber 29. Bellows 28 isconnected to an air supply channel 32 at a bottom side remote fromchamber 29. By supplying air to bellows 28 via air supply channel 32,the toothed (33) surface 34 of bellows 28 that faces towards chamber 29is moved in the direction indicated by arrow P4 towards the wall 35 offeed-through channel 30. If a fibre extends through feed-through channel30, said fibre is pressed against the wall 35 of feed-through channel 30by surface 34. When subsequently surface 34 is moved in a directionopposed to the direction indicated by arrow P4, the fibre will bereleased again. As is shown in FIG. 3, a gap is present to the left offeed-through channel 30, into which gap the knife 17 can be moved.

FIG. 4 shows the venturi device 12 according to the invention, whichcomprises a holder 36, which accommodates ends of tubes 10 and 13. Theend of tube 10 extends partially into the end of tube 13. An annular gap37 is present between tube 10 and tube 13. Said annular gap 37 opensinto an annular air supply chamber 38 on a side that faces towards tube10. Air supply chamber 38 is further connected to an air supply channel39. Annular gap 37 opens into tube 13 on a side remote from air supplychamber 38. Compressed air that is being supplied from air supply line39 is forced through annular gap 37 via annular chamber 38. As soon asthe air exits annular gap 37, the air in tube 13 will expand, thusexerting a force in the direction indicated by arrow P5 on the fibre 40that is present in tube 13, as a result of which fibre 40 will be movedin the direction indicated by arrow P5.

The overall process of inserting a fibre into a surface will now beexplained with reference to FIGS. 1-4.

Frame 3 is moved across a surface that is to be provided with syntheticfibres by means of caterpillar tracks 2. During said movement, a fibre40 is unwound from each roll 4, which fibre is moved between the wheels7, 8, which rotate in opposed directions, via feed-through tube 6.Wheels 7, 8 pull fibre 40 from roll 4. Fibre 40 is introduced into tube11 on a side remote from feed-through channel 6 and guided into theventuri device 12. In the venturi device 12, the air that is suppliedvia air supply channel 39 exerts a propelling force on fibre 40 in thedirection indicated by arrow P5, as a result of which fibre 40 is guidedfurther in the direction indicated by arrow P5. Once rolls 7, 8 havemade a desired number of revolutions, the front end of fibre 40 will bepositioned near end plate 21. Then the fibre 40 is pressed againstsurface 35 of feed-through channel 30 in the above-described manner bymeans of fibre clamping device 18. Following that, fibre 40 is cut offby means of knife 17 of fibre cutting device 15.

After fibre 40 has been cut off by means of knife 17 of the cuttingdevice 15, the clamping action that is being exerted on fibre 40 bymeans of clamping device 18 is released, after which the fibre 40 willbe loose in feed-through channel 19. Then the pin 23 of fibre insertiondevice 22 is moved in the direction indicated by arrow P3, whereby pin23 presses fibre 40 into the feed-through channel 24 and through opening26. Then the fibre is pressed further into the surface that is presentunder plate 25 by means of pin 23. Once pin 23 has been pressed thedesired distance into the surface, pin 23 is moved in the directionopposed to the direction indicated by arrow P3. In order to prevent thesurface being moved in this direction as well, press-down plate 25 islikewise moved in the direction indicated by arrow P3 by means ofbellows 27 when pin 23 is being moved in said direction, and caused topress down on said surface. Only when pin 23 has been removed from thesurface is plate 25 moved, likewise in the direction opposed to thedirection indicated by arrow P3. Fibre 40 is now disposed in saidsurface and device 1 can be moved a desired distance by means ofcaterpillar tracks 2. While device 1 is being moved, a fibre 40 isunwound from roll 40 again by means of rollers 7, 8, and positionedunder insertion pin 23 in the above-described manner, after which a nextfibre 40 can be pressed into the surface. In this manner it is possibleto insert a fibre having a length of 43 cm, for example, 20 cm deep intoa surface every three seconds, as a result of which the two fibre endswill each project 1.5 cm above the surface. The insertion of the fibresinto the surface, which further comprises grass, for example,strengthens the turf. When the grass is cut to a length of at least 2cm, the synthetic fibres that are present therein will not form animpediment when the grass is being mown.

It is possible to move the fibre insertion device 22 towards or awayfrom fibre cutting device 15. This makes it possible to cut the fibre toany desired length, depending on the depth to which the fibre is to beinserted into the surface.

FIG. 5 shows an embodiment of a device 51 according to the invention,which comprises a fibre insertion device 55, which differs from thefibre insertion device 5 of FIGS. 1-4 on a number of points.

Fibre insertion device 55 comprises a fibre clamping and cutting device56, which includes a stationary block 57 and a bar 58 which is rotatablysupported therein. A passage 60 is formed through block 57 and bar 58 ina direction transversely to central axis 59, the central axis 61 ofwhich coincides with central axis 14. Bar 58 is connected, via an arm62, to one end of a rod 64 which is movable in a pneumatic cylinder 63.Cylinder 63 is pivotally connected to frame 3 on a side remote from arm62. Fibre insertion device 55 furthermore includes a guide tube 65,which is disposed on a side of the fibre insertion pin 23 remote fromdevice 56. Guide tube 65 is reciprocable in the directions indicated bydouble arrow P10, from a first position, in which an uninterruptedpassage is provided through tube 13 and tube 65, to a second position asshown in FIG. 5, in which a passage is clear for fibre insertion pin 23.

The operation of the fibre insertion device 55 is as follows. A fibre isintroduced into tube 13 by means of rollers 7, 8 and venturi device 12in a similar manner as with fibre insertion device 5, and carriedonwards to a position near the end of tube 65. Tube 65 occupies saidfirst position thereby. Then the pneumatic cylinder 63 is energized, asa result of which rod 64 is moved in the direction indicated by arrowP11. The movement of rod 64 causes arm 62 and the bar 56 connectedthereto to pivot about central axis 59 in the direction indicated byarrow P12. This pivoting movement brings an edge 66 of passage 60 in bar58 into contact with the fibre, as a result of which the fibre is at thesame time clamped down and cut off upon further pivoting of bar 58.

Then bar 58 is pivoted in the direction indicated by arrow P12 by movingrod 64 in a direction opposed to the direction indicated by arrow P11,until the passage 60 in bar 58 extends parallel to central axis 14.

After the fibre has been cut off, tube 65 is moved to a second position,after which fibre insertion pin 23 is moved in the direction indicatedby arrow P3 and the fibre is inserted into the surface.

FIGS. 6 and 7 show a second embodiment of a fibre clamping and cuttingdevice 56, wherein arm 62 is pivotable between two stops 70. The bar 58comprising the passage 60 is thereby moved from the first position, inwhich passage 60 is co-axial with tube 13, to a second position, inwhich passage 60 includes an angle with tube 13. In this latter positionthe fibre is clamped down and simultaneously cut off. In order to ensurethat the fibre can only be cut off near the left-hand side of passage60, seen in FIGS. 6 and 7, the diameter d1 of tube 13 near the left-handside is smaller than the diameter d2 near the right-hand side.

In order to ensure a proper cutting action between the edges of bar 58and tube 13, cutting device 56 is fitted with a plastic cap 71, by meansof which bar 58 is firmly pressed down on block 57 in radial direction,so that it will abut firmly against block 57 near cutting edge 66.

Bar 58 remains rotatable about central axis 59 thereby.

1. A method for inserting synthetic fibres into a surface, comprising:unwinding a fibre from a roll; transporting the fibre through a firsttube to a position under an insertion element by an air flow; after thetransporting, cutting the fibre off to a desired length, whereupon thefibre is pressed into the surface by an insertion device, wherein thefibre is cut off by a rotatable element that is rotatable about an axis,which rotatable element is provided with a passage that is co-axial withthe first tube in a first position of the rotatable element and thatincludes an angle with the first tube in a second position of therotatable element, in which position the fibre is cut off.
 2. A methodaccording to claim 1, wherein the insertion element further includes aguide tube that is co-axial with the first tube, which guide tube ispositioned on a side of the first tube remote from the insertion elementand which is axially movable with respect to the first tube from a firstposition, in which a substantially uninterrupted passage between theguide tube and the first tube is provided, to a second position, inwhich a passage for the insertion element is provided.
 3. A methodaccording to claim 1, wherein in the transporting the fibre is passedthrough a venturi device, and wherein the air flow that carries thefibre is generated in the venturi device.
 4. A device configured tocarry out the method according to claim 1, which device comprises: atleast one roll on which the fibre is wound; an unwinding device forunwinding the fibre from the at least one roll; a fibre feed-throughdevice including the first tube; a fibre cutting device; the insertionelement; and the venturi device for transporting the fibre from theunwinding device by an air flow, wherein the fibre cutting deviceincludes a fibre clamping and cutting device including the rotatableelement that is rotatable about the axis, which rotatable element isprovided with the passage that is co-axial with the first tube in thefirst position of the rotatable element and that includes the angle withthe first tube in the second position of the rotatable element.
 5. Adevice according to claim 4, further comprising a guide tube that isco-axial with the first tube, which guide tube is positioned on a sideof the first tube remote from the insertion element and that is axiallymovable with respect to the first tube from a first position, in which asubstantially uninterrupted passage between the first tube and the guidetube is provided, to a second position, in which a passage for theinsertion element is provided.
 6. A device according to claim 4, whereinthe fibre feed-through device includes two opposed wheels that arerotatable in opposed directions, which wheels are in contact with eachother in a feed-through plane, while the venturi device includes anelongate tube, one end of which is positioned opposite the two wheels inthe feed-through plane.
 7. A device according to claim 6, wherein oneend of the first tube remote from the two wheels is positioned in afurther tube, wherein an annular air supply opening is present betweenthe first tube and the further tube.
 8. A device according to claim 4,further comprising a fibre clamping device positioned between the fibrecutting device and the insertion element.
 9. A device according to claim8, wherein the fibre clamping device includes an air-actuated bellow.